This invention relates to clamps for flexible tubes and more particularly to clamps for use in surgical applications.
Clamps for shutting off the flow of fluid through flexible tubing are of particular importance, for example, in regulating the flow of intravenous fluids and in surgical applications requiring blood vessels to be closed to minimize blood loss. With respect to flexible tubing outside the body the clamps must be designed to effectively block the flow of fluids and prevent the inadvertent opening of the clamp. During surgery, a clamp must be capable of being efficiently and quickly placed on a blood vessel and structured so that the vessel will not slip from the grasp of the clamp. In some instances, the clamps must be left in the body for extended periods of time requiring that the clamp be formed of a material compatible with body tissues.
Various clamps are currently in use, the most typical of which is a wire wound metal clamp spring biased in the clamping or closing position so that the clamp must be open for the insertion of a tube therein. Flexible plastic tubing has a tendency to slip from the grasp of such clamps creating unnecessary complications and requiring constant attention.
U.S. Pat. No. 2,463,451 (Yates) discloses a U-shaped flexible clamp with clamping surfaces at the free ends of the clamping members. The clamp is biased open and closed by an elongated handle having a cam surface contacting one of the clamping members. The clamping surfaces in Yates are broad pads which would tend to distribute the clamping force over a wide area. Such a distribution is undesirable in applications wherein a tube or vessel must be completely closed to fluid flow. Additionally, the Yates clamp may be inadvertently opened by the accidental manipulation of the handle.
Additionally, U.S. Pat. No. 3,766,925 (Rubricius) and 3,162,475 (Dinger) each discloses a surgical clamp molded of plastic material. These clamps are difficult to utilize in internal body areas that are relatively inaccessible since the surgeon must grasp the clamp about its tube clamping portion to effectively place the clamp. The Rubricius device is also impractical where the vessel to be clamped is not one that has been cut. The placement of the Rubricius clamp about such a vessel requires the complex manipulation of its parts.
The prior art, thus, does not overcome all the problems associated with clamps for flexible tubes, as in dialysis applications, or with clamps for surgical use to block blood flow in vessels.
The present invention overcomes these problems in that it is a cam-actuated positive locking clamp easily manipulatable by an operator using a single hand. Further, it has serrations along the clamping surface to prevent slippage of the flexible tubes. The clamp is provided with a locking device to prevent the accidental opening of the clamp. Additionally, the clamp may have elongated curved clamping members to facilitate insertion of the clamp into relatively inaccessible internal body locations.